A small size and high efficiency laser oscillation apparatus capable of obtaining high output and high beam quality laser light is provided. First waveguide (21) (refractive index=n1) for transmitting excitation light, second waveguide (22) composed of core (23) (refractive index=n3) for generating laser...http://www.google.fr/patents/US7283293?utm_source=gb-gplus-shareBrevet US7283293 - High efficiency optical amplifying fiber
